Alvin Tru-Flex II Flexible Curves

The Tru-Flex II Flexible Curve features a lightweight aluminum core that is easily shaped into any curve — and then holds it for accurate drawing.

The Tru-Flex II features convenient inking edges for pen and marker use, and flat edges on both sides for pencil drawing. In includes color-coded black inch graduations in 16ths and 32nds, and color-coded red metric graduations in millimeters and centimeters.

What can I say, these flexible curves are hard to get perfectly smooth bends in sometimes, handy for some uses now and then, they are all pretty much the same, this one does have an inking edge though. Overall they are an imperfect invention no matter who made them...